Eterna S.A. is a Swiss watch manufacturer established in 1856 and currently part of the Citychamp group.

On 7 November 1856 the physician Dr. Josef Girard and the school teacher Urs Schild founded the raw movement manufacturer Dr. Girard and Schild Ebauches in Grenchen. The company was formally organized eight years later, as production grew.

In 1866, Girard retired from the company, selling his shares to Urs Schild for CHF 35,000. Schild as sole owner introduced the production of complete mechanical watches under the new name, Präzisionsuhren-Fabrik Gebrüder Schild (Precision Watches Factory Schild Brothers). In the following decades, greater mechanization was slowly introduced, including water- and steam-powered machines.

Since 1875 (or perhaps as late as 1889), the first watches signed with the Eterna name on the dial appeared. Beginning in 1878, the company also produced its own cases and dials, becoming a complete manufacture. Urs Schild became a National Councilor in 1882 but died in 1888. The company was taken over by his brother, Adolph Schild, his widow, and his sons Max and Theodor. The company was soon renamed Gebr. Schild & Co. even as the brand name Eterna became more prominent. Adolph Schild left in 1896 to found A. Schild SA (ASSA), a movement maker that would remain mostly independent of the Schild operations until the creation of the modern ETA in 1979.

Max Schild traveled to the United States around 1890 to see the mechanized American production model. He returned with machines to help automate the company's production, but these ideas proved unpopular. He left the company and his brother, Theodor Schild became the head of the company in 1899, serving in that capacity for 33 years. The company was then known as Schild Fréres but officially changed its name to Eterna in 1905.

Eterna was an early proponent of wristwatches after the turn of the century, patenting “safety” lugs in 1904 and introducing the world's first alarm watch prototype in 1908. That watch went into mass production in 1914. Eterna was gaining renown in those years, winning the Grand Prix at the Swiss National Exhibition in 1910. By the 1920's, the company had grown to produce over a million watch movements each year, introducing mens products like a cigar lighter watch and protected self-winding sports watch, the Hexa. The company continued strength in women's watches as well, with a tiny baguette movement rivaling Jaeger-LeCoultre's Cal. 101.

The great depression of the 1930's hit the Swiss watch industry hard, and the Swiss government and banks moved to consolidate the vast number of small suppliers to reduce disastrous “dumping” of product. With Eterna one of the strongest companies in the space, many component manufacturers were consolidated within the company's ETA AG movement arm. Watch operations remained separate as Eterna AG under Theodor's son, Rudolf Schild-Comtesse. Both parts of the company became part of the ASUAG holding company in 1932, with ETA falling under the Ebauches SA umbrella. Although A. Schild was a founding member of Ebauches SA, it remained separate from ETA/Eterna until 1979.

Development continued throughout the 1930's and 1940's, with Eterna introducing chronographs, sweep central seconds and the first automatic movement in 1938. The Eterna-Matic of 1948 was a watershed for the industry, with its ball bearing-supported central rotor setting the standard from then on. The five balls used to support the rotor became the company's logo in the following decades.

Eterna grew with the Swiss watch industry throughout the 1950's, introducing the famous Kon Tiki watch to celebrate Thor Heyerdahl's 1947 journey, which had included Eterna watches. Other important pieces from that decade include the very-thin Centenaire automatic watch and the Golden Heart, a women's watch with a large gold rotor that became a Hollywood favorite.

In 1962, Eterna introduced the ultra-thin Eterna-Matic 3000 Dato, the thinnest-yet automatic men's watch with a date mechanism. For women, the 4 mm thin Sahida was a favorite thin watch.

As electronic watches rose to prominence in the 1970's, Eterna introduced their own tuning fork watch, the Eterna Sonic, as well as a quartz watch in 1974. The 1979 Estrellita Quartz was the smallest water-resistant watch ever made, wit a 1.06 gram movement. In the 1980's, Eterna's Museum line competed in the ultra-thin category, with a .98 mm watch the crowning achievement.

In 1982 Eterna was bought by the SMH trust. This emerging conglomerate, later to become Swatch Group, needed access to Eterna's holdings in ETA, the movement maker. Keeping ETA, SMH quickly spun the Eterna brand off to the PCW Group, part of Prof. Ferdinand Alexander Porsche's F. A. P. Beteiligungs GmbH (“Porsche Design”) group. In 1988, Eterna purchased Sosclan, maker of Fiorucci-branded watches and managed by Claude R. Schild, son of long-time Eterna and ETA director Rudolf Schild-Comtesse. The younger Schild became manager of Eterna, returning the company to the founding family, from 1988 through just 1990. He was replaced by SMH veteran Herbert W. Arni, who would run Eterna through the 1990s.

The Porsche Design license was long held by IWC, but this agreement expired in April of 1998. From then on, production of Porsche Design watches was taken on by Eterna. One major innovation of this era was the 2004 Porsche Design Indicator chronograph. Introduced at Baselworld, the Indicator was the first chronograph to feature mechanical digital hour and minute counters.

Although stripped of ETA, Eterna set about once again designing in-house movements in the 2000's. In 2004, Eterna once again introduced their own movement, Cal. 6036. This was followed in 2005 by the automatic Cal. 3030 and Cal. 6037 in 2007. Eterna returned to their roots with the introduction of the ball bearing-supported mainspring barrel, called “Spherodrive” and introduced in 2009. Another major advance was Cal. 3510, a hand-wound eight-days movement with the Spherodrive barrel, introduced in 2010.

Eterna was purchased in 2012 by International Volant Ltd, a subsidiary of China Haidian (now Citychamp) that also includes Corum. That same year, Eterna introduced Cal. 3843 in the Advantic.

In 2013, Eterna announced Calibre 39, a modular in-house movement. The project or five years development, Cal. 39 can be equipped in various configurations, including as a column wheel chronograph. The company plans to make this movement available to other Swiss watchmakers looking for an alternative to ETA movements. They claim that over 70% of the movement is sourced from Grenchen.

Adolph Schild left the company in 1896 and founded the Adolph Schild S.A. (also called ASSA). Amid economic issues in 1926, ASSA was merged with FHF to become Ebauches SA. This was reunited with Eterna when it was merged into ASUAG in 1931, though movement manufacturing continued under the A. Schild name for decades. These familiar “AS”-marked movements were used by many companies into the 1970's. But the quartz crisis ended production, with ASUAG's movement assets merging with ETA in 1979. This merger reunited all components of the Schild family watchmaking operations for the first time in almost 100 years.

The company belongs to the pioneers of wristwatches with automatic winding and in 1948 introduced the central rotor with miniature ball bearing (at the automatic watch model „Eterna Matic“).

Because of the superior importance of this development Eterna has the principle of the ball bearing weight segment also shown symbolically in the logo of the brand.

• Eterna